mysql - 如何转义 MySQL 中的特殊字符？

Question

例如:

select * from tablename where fields like "%string "hi"  %";

错误:

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'hi" "' at line 1

如何构建此查询？

Answer 1

The information provided in this answer can lead to insecure programming practices.

The information provided here depends highly on MySQL configuration, including (but not limited to) the program version, the database client and character-encoding used.

参见 http://dev.mysql.com/doc/refman/5.0/en/string-literals.html

MySQL recognizes the following escape sequences.
\0     An ASCII NUL (0x00) character.
\'     A single quote (“'”) character.
\"     A double quote (“"”) character.
\b     A backspace character.
\n     A newline (linefeed) character.
\r     A carriage return character.
\t     A tab character.
\Z     ASCII 26 (Control-Z). See note following the table.
\\     A backslash (“\”) character.
\%     A “%” character. See note following the table.
\_     A “_” character. See note following the table.

So you need

select * from tablename where fields like "%string \"hi\" %";

虽然作为Bill Karwin notes below , 对字符串分隔符使用双引号不是标准 SQL，因此最好使用单引号。这简化了事情:

select * from tablename where fields like '%string "hi" %';